Endothelial thromboxane production plays a role in the contraction caused by 5-hydroxytryptamine in rat basilar arteries.
J J Descombes, M Devys, M Laubie, T J Verbeuren
Index: Eur. J. Pharmacol. 243(2) , 193-9, (1993)
Full Text: HTML
Abstract
The goal of the present study was to characterize the role of the endothelium in the 5-hydroxytryptamine (5-HT)-induced contraction of the rat basilar artery. Rat basilar artery segments were mounted in myographs to study their isometric tension development. 5-HT caused dose-dependent contractions that were minimally affected by endothelium removal. The dose-response curve obtained with the 5-HT1 receptor agonist, 5-carboxamidotryptamine (5-CT), was biphasic in arteries with endothelium; removal of the endothelium eliminated the first phase of the contraction. The 5-HT2 receptor antagonist, ketanserin (30 nM), shifted the dose-response curve to 5-HT to the right; in arteries with endothelium, the curve became biphasic. Ketanserin inhibited the second phase of the dose-response curve to 5-CT. The mixed 5-HT1/5-HT2 receptor antagonist, metergoline (30 nM), shifted the dose-response curve to 5-HT non-competitively to the right and depressed both phases of the dose-response curve to 5-CT. In basilar arteries with endothelium and treated with ketanserin, the thromboxane A2 receptor antagonist, ICI 192605 (1 microM), significantly decreased the responsiveness to 5-HT and the dose-response curve for 5-HT became monophasic. ICI 192605 and the thromboxane A2 synthase inhibitor, ridogrel (10 microM), both suppressed the first phase of the dose-response curve to 5-CT. These data indicate that both endothelial 5-HT1 and smooth muscle 5-HT2 receptors participate in the contractions caused by 5-HT in the rat basilar artery.(ABSTRACT TRUNCATED AT 250 WORDS)
Related Compounds
Related Articles:
Thromboxane and isoprostane share the same prostanoid receptors to increase human placental tone
2011-12-01
[Placenta 32(12) , 941-8, (2011)]
2009-02-01
[Clin. Exp. Allergy 39(2) , 236-45, (2009)]
1995-07-14
[Eur. J. Pharmacol. 280(3) , 293-9, (1995)]
1997-07-01
[Br. J. Pharmacol. 121(5) , 875-82, (1997)]
1997-03-01
[J. Lipid Mediat. Cell Signal. 15(3) , 249-54, (1997)]